How popular is Charmyn?

Charmyn is a rare first name for females. Charmyn is also a unique last name for all people. (2000 U.S. Census)

Which version is better?

with its source form and related girl names. Popular varying forms of Charmyn (not ranked) ranked in the Top 2000 are Charmaine, Sharmaine and Sharman. Other forms, like Sharmayne, are uncommon. Adoption of these forms of Charmyn was well-received among parents during 1950-1959 (average #1310), but now, the version Charmaine has become less trendy. (2015 Birth Statistics)